Expanding bit.



No. 851,783. PATENTED APR. 30, 1907.

A. E. SWANSON.

EXPANDING BIT.

APPLICATION FILED MAR. 5.190s.

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No. 851,783. PATENTED APR. 30, 1907.

' A. E. SWANSON.

EXPANDING BIT.

APPLICATION nun MAR. 5.1906.

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AYEL E. Sl/VANSON, OF CHICAGO, ILLINOIS.

EXPANDING BIT.

Specification of Letters Patent.

Patented April 30, 1 907.

Application filed March 5,1906. Serial No. 304.883.

To (til whom it may concern:

Be it known that I, AXEL E. Swanson, a citizen of the United States ofAmerica, and a resident of Chicago, county of Cook, and State ofIllinois, have invented certain new and useful Improvements in ExpandingBits, of which the following is a specification.

The main objects of this invention are to rovide an improved, efficient,and durable form of bit for boring tapered holes, and to provideimproved mechanism for operating a bit of this class whereby the taperedhole will be completely formed in a single operation. These objects areaccomplished by the device shown in the accompanying drawings, in which:

Figure 1 is a side elevation of a boring tool constructed according tothis invention and showing also the form of tapered hole which. thetoolis adapted to bore. Fig. 2 is a similar elevation of the same,showing the sleeve and its cutter blade in section. Fig. 3 is an endview of the same. Fig. 4 is a side eleva tion of a boring machine fittedwith this form of boring tool. Fig. 5 is a top plan of the same. Fig. (5is a detail of the connection between the sleeve 5 and its operatingrods 24.

In the construction shown in the drawings, the bit 1 is provided with ashank having uniform cross-section throughout the greater part of itslength. This bit is provided with the usual center point 2, and theusual cutting blades 3 and *1. A sleeve 5 is mounted to slidelongitudinally along the shank of the bit 1. The sleeve 5 has rigidthereon a cut ting blade 7. The shank is preferably prismatic or square,so as to cause the sleeve 5 to rotate therewith, and is curved or bentlongi tudinally, so that one face (5 thereof will serve as a guidingsurface for causing the blade 7 to gradually increase its cutting radiuswhen the sleeve 5 is shifted toward the cutting end of the bit. Thesurface 8 of the shank is curved to correspond with the surface 6.

The sleeve 5 has its inner surface so formed as to bear on the shank atfour )oints 9 and 1-0 of relatively small area and located near theopposite ends of the sleeve. The walls of the sleeve 5 which are opposedto the surfaces 6 and 8 are cut away between the points 9 and 10 so asto permit the sleeve to readily follow the curvature of the shank 1. Thesleeve 5 has an annular groove at 11 to provide a swiveled connection.with the shifting links as will be hereinafter described.

A machine for operating this form of boring tool is illustrated inliigs. 4 and 5. The supporting frame 12 has a vertically disposed shaft13 journaled therein and mounted to slide longitudinally in its bearings14. The shaft 13 is driven by a belt 15 and a Wide ulley 16 arranged topermit of the desired ongitudinal shifting of the shaft 13. The shaft 13has a chuck 17 at its lower end adapted to grip the shank 1 of the bitand securely hold the same in axial alinement with said shaft. The shaft13 is shifted in its bearings by means of a lever 18 fulcrumcd at 19 inthe supporting frame and having swiveled connection at 20 with the shaft13. The lever 18 is connected by means of a link 21 with a treadle lever22.

The sleeve 5 has swiveled connection with a collar 23 by means of whichthe said sleeve is shifted along the shank of the bit 1 when said bit islowered. The collar 23 is pivot ally connected between a pair of rods orlinks 24 which are slidably mounted in lugs 25 at opposite sides of thebearings 14, and which extend parallel with the shaft 13 on the oppositesides thereof. These links are slid in their guides by means of a pairof levers 26 which are fulcrumed at 27 on the supporting frame 12 andconnectedwith the link 21 by the same pivot 28 which connects said linkwith the lever 18. The fulcrums 27 are located between the pivot 28 andthe fulcrum 19 so as to cause the sleeve 5 to shift at a greater speed.than the bit is so shifted. The pivot 28 passes through an elongatedslot in the lever 18 to provide for the play which is required at thispoint.

The connection between the links 24 and the sleeve 5 is preferably ofthe gimbal type as illustrated in Fig. 6 so as to permit the sleeve 5 tobe tilted as in Fig. 1, while being rotated. The rods 24 are adjustableby means of a turn buckle 29 to provide for variation in the shifting ofthe sleeve 5 with respect to the bit 1. In this way the operator is ableto control the distance to which the bit 1 will penetrate the block 30which is being bored, before the blade 7 commences to cut the block andtaper the hole. The turn buckles 29 should be so adjusted that thecutter 7 will reach its extreme position at the lower end of the bit asin Fig. 1 when the bit has penetrated the block to the desired depth.

The operation of the device shown is as follows: Assumelthat the shaft13 is being continuously driven by the belt 15, and that the bit andsleeve 5 are normally urged to a lifted position by the counterweight 31on the treadle lever 22. The operator then places the block 30 which isto be bored upon the table 32 and by pressing downward upon the treadlelever 22, causes the bit to penetrate the block as the link 21 is pushedupward, the lever 18 forces the bit 1 down ward, and the levers 26simultaneously force the sleeve 5 downward. On account of the differencein length of the corresponding arms of the levers 18 and 26, the descentof the sleeve 5 is more rapid than that of the bit. This causes thecutter 7 to follow the bit 1 into the hole which is bored thereby and togradually overtake the cutter of the bit until said bit has reached thelimit to which it is desired to bore. On account of the adjustment ofthe turn buckles 29, the cutter 7 will by this time have also reachedthe bottom of the hole cut by the bit. Since the sleeve 5 can move nofurther along the bit, further descent of the bit is prevented. It ispreferred to adjust the table 32 on the supporting frame, to suchposition that the sleeve 5 will arrive at its lower limit of movementalong the bit 1 when the treadle 22 has been pushed to the lower limitof its movement.

What I claim as my invention and desire to secure by Letters Patent is:

1. A device for boring tapered holes comprising a bit having a shankbent toward one side at its lower end, and a sleeve slidably mounted onsaid shank and having thereon a cutting blade, said sleeve being adaptedto tilt so as to cause said blade to shift outward when said sleeve isslid downward on said shank.

2. A device of the class described comprising a shank, a sleeve slidablymounted on said shank and having thereon a cutting blade, a guidingsurface on said shank adapted to tilt said sleeve for causing said bladeto shift outwardly when said sleeve is moved downward along said shank.

3. A device of the class described comprising a shank, a sleeve slidablymounted on said shank and having thereon a cutting blade, said sleevebeing secured against rotation relatively of said shank, a guidingsurface on said bit adapted to tilt said sleeve for causing said bladeto shift outwardly when said sleeve is moved downward along said shank.I

4. A device of the class described comprising a bit, a sleeve slidablymounted on said bit and having thereon a cutting blade,

a guiding surface on said bit adapted to tilt said sleeve for causingsaid blade to shift outwardly when the sleeve is moved downward alongsaid bit, means for rotating said bit, and mechanism for urging said bitdownwardly and adapted to simultaneously cause A shank of the bit.

of a frame, a shaft journaled therein, a bit secured at one end of saidshaft and having its point in axial alinement therewith, a sleeveslidably mounted on the shank of said bit and having thereon a cuttingblade, a guiding surface on said shank adapted to cause said sleeve totilt when shifted along said shank for moving said blade downwardly,means for rotating said shaft, mechanism for shifting said shaftlongitudinally in its bearings, and mechanism adapted to shift saidsleeve at a different rate of speed while said shaft is being shifted.

6. In a machine of the class described, the combination of a frame, ashaft journaled in said frame and slidable longitudinally in itsbearings, a bit mounted on said shaft, a sleeve slidably mounted on saidbit and having thereon a cutting blade, one or more guiding surfaces forcausing said blade to shift outwardly when said sleeve is moved towardthe point of said bit, means for shifting said shaft longitudinally inits bearings and adapted to cause said sleeve to simultaneously shiftalong said bit.

7. In a machine of the class described, the combination of a frame, ashaft j ournaled in said frame and slidable longitudinally in itsbearings, a bit mounted on said shaft, a sleeve slidably mounted on saidbit and having thereon a cutting blade, one or more guiding surfaces forcausing said blade to shift outward from the axis when said sleeve ismoved toward the point of said bit, a lever fulcrumed on said frame andconnected with said shaft for shifting the same longitudinally in itsbearings, a second lever fulcrumed on said frame, a link connecting saidlever with said sleeve, and means for simultaneously swinging saidlevers on their fulcrums, the arms of said levers being respectively ofdifferent lengths, whereby said bit and sleeve will be shifted atdifferent speeds. I

8. In a machine of the class described, the combination of a frame, ashaft journaled in said frame and slidable longitudinally in its sleeveslid ably mounted on said bit and having thereon a cutting blade, one ormore guiding surfaces for causing said blade to shift outward from theaxis when said sleeve is moved toward the point of said bit, a leverfulcrumed on said frame and connected with said shaft for shifting thesame longitudinally in its bearings, a second lever fulcrumed on saidframe, a link connecting said lever said sleeve to shift downwardlyalong the 5. In a boring machine, the combination bearings, a bitmounted on said shaft, a-

with said sleeve, said link being adjustable Signed at Chicago this 1stday of March, for controlling the relative movements ofl 1906.

said sleeve and bit, means for simultaneously swinging said levers ontheir fulerums, the arms of said. levers being respectively of differentlengths, whereby said bit and sleeve l Will be shifted at differentspeeds.

AXEL l1). SWANSON.

Witnesses:

.L. SWANSON, L. A. SMITH.

